a pair of croaking gouramis. They max out at around 3/4-1" and really don't move much. Just run like a tetra whisper air driven filter, get your self a chunk of java moss and some sort of wood. I use cutting from the ends of manzanita branches for my 2.5 since their skinny and don't take up any room. And a low powered light. Then throw in a piece of Indian almond leaf or peat and your all good to go. Very fun tiny fish! Also you might be able to get away with 1 Scarlet Badis instead of the croakers if you had a steady live brine shrimp colony.